Read that passive ones aren't supported.
Rupal Rajwar wrote:
TwinAx Passive cables are yet not supported on the VNX models . Its only the active ones.
Have a broader look : http://www.emc.com/collateral/hardware/white-papers/h8217-introduction-vnx-wp.pdf
However I guess things have changed since Jun 27, 2012.
passive are still not supported (as far as i know), but you can buy active from Cisco or other vendors (probably cheaper than what EMC resells them for)
I have linked the docs in Elab and their pages that also outline what Twinax sfp's are support in the kb
You are correct also EMC do not support passive twinax cables